I had this problem and solved it. Perhaps this will be helpful for other folks, though I don't know if its the only situation that can cause the problem...
In my case, the product named in the error had inactive sub-products. After removing them, the error changed to accuse the next product with inactive sub-products of being a duplicate. Eventually, I was able to remove all inactive sub-products and successfully switch to categories.
Steps:
- Change the filter in the "Products & Services" list to show "All" products, not just "Active".
- Locate the first "Active" product that has "Inactive" sub-products. Helpfully, this is the product named in the error (unhelpfully, the error message does not correctly identify the issue).
- Make the Sub-products "Active"
- Edit each 'formerly inactive' sub-product to
- uncheck the "is a sub-product" option
- rename the sub-products so that they're easy to find in the next step. I put a 'z' in front: zProduct1, zProduct2, etc.
- Make the sub-products inactive again.
I had already removed my active product hierarchy at this point, so I don't know if any sub-products will cause the issue. But I know the inactive ones did, so hopefully removing them will help folks out before they need to edit a long list of active sub-products...
